tailieunhanh - Combating NOx from refinery sources using SCR by Hans Jensen-Holm and Peter Lindenhoff

Refinery SCR applications SCR for steam cracking and reformer furnaces Chromium deactivation mechanism SCR DeNOx in fluid catalytic cracking units (FCCU) SCR design issues ABS condensation considerations Catalyst selection Catalyst cleaning | HALDOR TOPS0E n Combating NOx from refinery sources using SCR by Hans Jensen-Holm Technology Manager and Peter Lindenhoff General Manager Air Pollution Control Catalyst Technology Haldor Tops0e A S HALDOR TOPSDE IT Combating NOx from refinery sources using SCR Page 2 of 31 List of contents 1 Summary 3 2 Introduction 4 3 The SCR DeNOx process and catalyst 5 The SCR process 5 The SCR catalyst 7 4 Refinery SCR applications 10 SCR for steam cracking and reformer furnaces 10 Chromium deactivation mechanism 11 SCR DeNOx in fluid catalytic cracking units FCCU 14 SCR design issues 14 ABS condensation considerations 15 Catalyst selection 17 Catalyst cleaning 17 5 Industrial experience 17 Chevron Phillips Cedar Bayou Texas USA ethylene plant 17 NOx reduction performance 19 Chromium accumulation in the catalyst 19 Fluid catalytic cracking units 21 Shell Deer Park Refinery Texas USA 21 ABS considerations 23 Ammonia mixing and SCR lay-out 23 Performance 24 Catalyst cleaning 25 Operation of the SCR 26 CITGO Petroleum Lemont Refinery Illinois USA 26 Design considerations 27 Operational performance 28 6 Conclusions 30 7 References 31 Information contained herein is confidential it may not be used for any purpose other than for which it has been issued and may not be used by or disclosed to third parties without written approval of Haldor Tops0e A S. RESEARCH I TECHNOLOGY I CATALYSTS HALDOR TOPS0E n Combating NOx from refinery sources using SCR Page 3 of 31 1 Summary The emission of nitrogen oxides or NOx is a major global pollution problem. The damaging effect of nitrogen oxides on health and environment is substantial. NOx contributes to acid rain resulting in deforestation and destruction of coastal and freshwater life. NOx further reacts in the atmosphere to form ground-level ozone bringing about the health-threatening yellowish smog in urban areas.